With the negative impact of conventional energy resources that have been used worldwide, there is a demand for using other resources such as wind energy. Tons of researches have been applied around the globe on the process of designing and manufacturing wind energy conversion systems. In the present chapter, we are concentrating on wind turbine blades' structural design process. The structural design of a wind turbine blade includes defining the wind turbine loads, selecting a suitable material, creating a structural model, and solving the model using the finite element method. This process will be repeated several times until a final design is achieved. The present chapter includes a discussion on the finite element method and wind turbine aeroelasticity.